Electric lamp



Nov. 1, 1955 H. s. WELLINGTON 2,722,668

ELECTRIC LAMP Filed Sept. 6, 1952 Inven tor: HavoLd S tanLe WeLLin cgbOn,

His A k tovnes.

United States Patent OfiFice 2,722,668 Patented Nov. 1, 1955 ELECTRIC LAMP Harold Stanley Wellington, Toronto, Ontario, Canada, assignor to Canadian General Electric Company, Limited, Toronto, Ontario, Canada, a corporation of Canada Application September 6, 1952, Serial No. 308,281 6 Claims. (Cl. 339-69) My invention relates to electric incandescent lamps and similar devices comprising a bulb having an electrical energy translating element sealed therein and a base mounted thereon. More particularly, my invention relates to bases for said devices which facilitate the installation and retention of such lamps in standard sockets.

The standard incandescent lamp base in general use at present comprises a center contact located centrally of the end of the lamp and a second or side contact consisting of a screw-threaded metal shell secured to the neck of the lamp. The standard socket for mounting such lamps comprises a threaded metal shell constituting one contact into which the threaded lamp is screwed until its center contact engages a cooperating contact'provided in the socket.

This arrangement necessitates a certain amount of care during the installation of such a lamp inasmuch as the axis of the threads must be relatively parallel and in proper rotational position before they will commence to engage. The lamp must then be rotated several turns before it is firmly in position. Under some conditions it can be seen that the relative positioning of the lamp and socket may be very hard to accomplish. Under all conditions the installation of a large number of lamps will be very time-consuming due to the number of revolutions necessary to install each one. Further, with many sockets, lamps under conditions of vibration may tend to work loose causing intermittent or complete failure of the central connection.

It is an object of my invention, therefore, to provide an improved base for an incandescent lamp which will facilitate its installation in a standard screw-thread type socket.

It is a further object of my invention to provide an improved base for an incandescent lamp which will hold it firmly in place in a screw-threaded socket even under conditions of vibration.

According to my invention a lamp bulb, having a neck of such dimension as to freely enter a screw-threaded lamp socket, is provided with a base in the form of a flat resilient member having a segmented edge. This resilient member, whose greatest dimension is slightly greater than the clearance diameter of the threaded socket shell, is anchored to the end of the neck of the bulb. The end of the neck of the bulb is so shaped as to permit the resilient member to flex upwardly as the lamp is pushed into the lamp socket. The bulb is thus resiliently retained in the socket by the engagement of the spring segments of the resilient member with the threads of the socket shell.

The invention may be better understood by reference to the following detailed description of one specific embodiment thereof as illustrated in the accompanying drawings.

Fig. 1 is an elevation partly in section of an electric incandescent lamp constructed in accordance with my invention inserted in a socket.

Fig. 2 is a section of the lamp on the line AA of Fig. 1, looking in the direction of the arrows.

Fig. 3 is a sectional View of the lamp bulb assembly, taken at the line AA of Fig. 1, before assembly of the lamp base thereon.

Fig. 4 is a detail plan view of the shell-engaging contact of the lamp.

Fig. 5 is a sectional view on the line B-B of Fig. 4.

Fig. 6 is a detail plan view of the center contact carrying insulating disc of the lamp shown in Fig. 1.

Referring to the drawings in which the same reference numbers designate the same parts throughout the several views, I have shown an incandescent lamp according to the invention mounted in a socket 1 provided with a standard screw-threaded shell contact 2 and a center contact 3. The center contact 3 may be of the customary springy nature.

The incandescent lamp illustrated comprises a glass lamp bulb 4 provided with a mount 5 of well-known construction consisting of a tubular glass stem 6 with lead-in wires 7, S sealed in its fused upper end or stem press 9. An electrical energy translation element or filament 10 is supported on the mount 5 within the bulb 4 and is connected at its ends to the said lead-in wires 7, 8. The stem 6 is provided interiorly thereof with a conventional exhaust tube 11 which, after exhaustion of the bulb and gas filling thereof, is tipped-off to hermetically seal the bulb. The stem 6 is fused at its outer end to the lower end of the neck 12 of the bulb. In accordance with my invention, the bulb neck 12 is formed to a diameter slightly less than the internal diameter of the socket shell contact 2. The fused glass end of the bulb joining the neck 12 to the stem 6 is formed slightly conical as indicated at 13, and the entrance to the hollow interior of the stem 6 is formed with an inwardly extending annular rib or lip 14 which serves as a locking shoulder for the lamp base. The rib 14 is provided with a pair of diametrically opposite inwardly projecting protuberances 15 (Fig. 3).

For the purpose of securing the lamp in the socket and making contact with the shell contact 2 of the socket, I provide a transversely extending spring metal disc 16 of a diameter slightly greater than the bulb neck 12. The disc 16 is divided into a plurality of segments 17 by radially extending slots 18, and the outer corners of the segments 17 are preferably rounded off as shown at 19 in Fig. 4. The disc 16 is provided with a central opening 20, and a plurality of flanges or lugs 21 are struck up from the material of the disc. Each flange or lug 21 is provided with an outwardly directed bent end, as shown at 22 in Fig. 5. The disc 16 is anchored to the neck end of the glass bulb 4 by inserting the flanges 21 into the stem tube 6 with the protuberances 15 located between adjacent flanges 21. It is apparent that rotational movement of the disc with respect to the glass bulb is prevented by the interengagement of the flanges 21 and the protuberances 15. Before disc 16 is placed in position, lead-in wire 8 is bent sideways and interposed between the disc and the end of the bulb.

After the disc 16is inserted in place it is locked on the bulb by retaining means in the form of a plug or button 23 of molded insulating material. The insulator button 23 is of a diameter the same as or slightly less than the diameter of the bulb neck 10, and it is provided on one side with a metal eyelet center contact 24 and on the other side with a central boss 25. The external configuration of the boss 25 is of a shape other than circular such that it fits into the central opening 20 of the disc 16 and presses or spreads out the flanges or lugs 21 of the disc, causing their bent ends to engage behind the rib 14 and thus lock the disc in place on the bulb against endwise movement and separation therefrom. The insulator button 23 is provided with a central aperture 26 which accommodates the tipped-off end of the exhaust tube 11 and through which-the1ead-in wire 7 extends to the center contact eyelet 24 to which it is soldered. The

other lead-in wire 8 is electrically connected to the disc 16 in any suitable manner.

It willbe seen-that the lamp of my invention may be quickly and easily inserted in a standard screw-threaded socket by pushingthe. base end of the lamp into the socket: The spring segments 17' of the disc 16, due to the conically relieved end surface 13 of the bulb neck, are free to'bend upwardly to the position indicated in dotted lines in Fig. l in which position they then ride over the surfaces ofthe shell threads and, upon passage thereover, will spring back into threaded engagement with the socket threads. When the lamp is pushed fully into the socket to, eflect engagement of its center contact 24 with the corresponding center contact 3 of the socket, one or more of the disc segments 17 will be engaged in the threads of the socket and a partial turn of the bulb 4 will cause its base end to be drawn into firm engagement with the. center socket contact 3. The individually bendable segments 17 will then distribute themselves in a helix in the thread of the shell. The lamp may be unscrewed from the socket in the usual manner, the segments 17 following the thread of the socket shell. The ends of the segments. 17' provide good electrical connection to the socket shell'contact, and due to their spring structure resist any tendency of the lamp to work loose in the socket under vibration.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electrical device for insertion into a screwthreaded socket, said device comprising a bulb having an electrical energy translation element sealed therein and a base mounted thereon, said base comprising a transverse resilient thin metal member having a segmented edge free to iiex, an insulator member anchoring said resilient member to said bulb and carrying a center contact, inter-engaging shoulder means on said bulb and resilient member locking them against relative rotational movement, and lead-in wires for said translation element connected to said resilient member andto, said center contact respectively.

2. An electrical device comprising a bulb having an indentation at one end thereof, an electrical energy translation element sealed in said bulb, a base mounted on said bulb and comprising a transverse metallic resilient member having an aperture and provided with a plurality of. upstanding lugs spaced aroundthe rim of said aperture,

said lugs extending into the said indentation in said bulb, retaining means forcing said lugs, outward into contact with the walls of said indentation to thereby hold the resilient member in fixed relation to said bulb, an end contact on said retaining means insulated from said resilient member, and lead-in wires electrically connecting said energy translation element to said resilient member and to the said end contact on said retaining means.

3. An electric lamp (or the like) for insertion into a screw-threaded socket, said lamp having a tubular neck of a diameter to freely enter the threaded shell of said socket and a base mounted on the end of the lamp neck, the said lamp neck having its outer end relieved to a substantial 4, degree, said base comprising a center contact for engagementwith the. center contactof the socketand aside contact for engagement with the shell of the socket, said side contact consisting of a transversely extending thin metal spring member anchored to the lamp in abutting relation to the end of the. lamp neck so that its outer extremities are free to bend into the space provided by the relieved portion ofthe. lamp neck to thereby assume a spring-contracted condition wherein the member will ride over the threads of.the socket when the lamp base is pushed thereinto and will springout into the socket threads to make firm holding contact with the shell by partial rotation of the lamp when so inserted in the socket, and inter-engaging shoulder means on said bulb' andspring member locking them against relative rotational movement.

4. An electric lamp or the like as defined in claim 3 in which the shell-engaging side contact comprises a spring metal disc of a diameter slightly greater. than that of said tubular neck and having a plurality of radial slots therein providing a plurality of independently bendable segments.

5. An electric lamp or the like. as defined in claim 3 in whichthe shell-engaging side. contact is provided with a plurality of upstanding flanges disposed about a central opening therein, said flanges cooperating with detents provided on the glassenvelope. of the lamp for anchoring itthereto.

6; An electric lamp or the like for insertion into a screw-threaded shell socket, said lamp comprising a bulb provided at one end with a tubular neck of a diameter to freely enter the threaded shell of the socket, a filament sealed'in said bulb, a base mounted on the end of the bulb neck, a hollow tubular glass stem fused to the end of the bulb neck,,.the fused end of the bulb neck being formed with a conical peripheral portion having its apex away from the bulb and the tubular stern having a rib therearound extending radially inward of the stem at its outer end, a flat metal shell-engaging side contact mounted on the end of the bulb neck and provided with projections adapted, to anchor it tothe said rib and with a plurality of radially extending spring fingers adapted to engage the shell contact of the socket and flex into the space provided.

by said conical portion of the bulb neck, a plug of insulating material carrying a center contact and engaging said projections to hold them in locking engagement with said rib, and lead-in wires for the lamp filament connected to said center contact and to said shell-engaging contact respectively.

References Cited in the file of this patent UNITED STATES, PATENTS 1,374,349 Benjamin Apr; 12, 1921 1,871,668- Dawson Aug. 16, 1932 1,987,427 Watson Ian. 8, 1935 2,192,943 Sumner Mar. 12, 1940 2,372,266 Frank Mar. 27, 1945 FOREIGN PATENTS 178,763, Great Britain May 27,' 1922 571,000 Great Britain. Aug. 1, 1945 

